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<== Date ==> <== Thread ==>

Subject: strange ca_array_get results on Linux
From: Jeffrey McDonald <[email protected]>
To: [email protected]
Date: Thu, 3 Sep 1998 13:07:51 -0500 (CDT)
Hi,

	Using a slightly modified version of caExample (which comes with
makeBaseApp), I download 200 parameters to a waveform record using a
ca_array_put command.  

The record is defined as: 

record(waveform, "$(user):waveForm1")
{
        field(DESC, "waveform record")
        field(NELM, "200")
        field(DTYP, "Soft Channel")
        field(FTVL, "USHORT")
}


from caExample.c, I do: 
	
    SEVCHK(ca_array_put(DBR_SHORT,200,mychid,(void *)indata),"ca_array_put
failure");
    SEVCHK(ca_pend_io(5.0),"ca_pend_io failure"); 
    SEVCHK(ca_array_get(DBR_SHORT,200,mychid,(void
*)outdata),"ca_array_get failure");
    SEVCHK(ca_pend_io(5.0),"ca_pend_io failure");

	
	I set the data equal to the array index, e.g. outdata[50] =50.  I
have defined the indata and outdata to be pointers to short.  

	When I read-back the data,  on the sgi OS, I get back exactly
what I expect.  When I read-back data on Linux (Red Hat 5.0), I get the
correct answer for the first 128 elements, for elements following 128, I
get:

	outvalue = invalue | 0xff00
	e.g. for outdata[199]= 65479 = 0xffc7
	(for those not hex-speaking  0xc7 is 199)

	I have checked to see that the correct values are in the waveform
record, and they are (the ca_array_put command works correctly). However,
when the ca_array_get is called, the values for the elements greater than  
128 are corrupted when they are returned on the Linux box -- but NOT on
the sgi.  

	Any ideas?  

	Thanks,

	Jeff

_____________________________________________________
Jeffrey McDonald, Florida State   [email protected]
FNAL MS 352			  phone   630-840-3983
Batavia, IL 60510                 fax     630-840-8886



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